- T-cell ALL HR (HR-R, HR-S, and HR-I): Patients receive cyclophosphamide IV over 30 minutes on days 29 and 64; mHD methotrexate IV over 24 hours on days 30, 65, 78, and 92; etoposide phosphate IV over 1-2 hours and cytarabine IV over 1 hour on days 80 and 94; oral mercaptopurine on days 64-70 and 92-98; oral thioguanine on days 78-84; and methotrexate IT on days 30, 43, 65, 78, and 92. Patients in HR-S and HR-I group are randomized* (randomization 1) to 1 of 2 arms to receive cytarabine and pegaspargase vs. clofarabine and pegaspargase.